Many restaurants, and in particular "fast food" restaurants, serve food such as chicken, fish, onion rings, and especially french fries, which are deep-fried in edible cooking fats or oils. Of these fried foods, french fried potatoes are particularly well liked by virtue of their textural dichotomy. This textural dichotomy manifests itself in a product which has a fairly crisp exterior and a fairly tender and moist interior. The method of deep frying has been found to be a particularly suitable way for imparting this desired textural dichotomy to french fried potatoes.
Deep frying is a process of cooking involving the direct transfer of heat from the frying medium to a cold or frozen food. In deep frying of french fried potatoes, cold or frozen uncooked or partially cooked (par-fried) french fried potatoes are typically deposited in a wire mesh basket. This basket is then immersed in a frying at or oil medium that has been heated to temperatures of approximately 335.degree. to 400.degree. C. (176.6.degree. to 190.5.degree. C.). The french fried potatoes can be immersed in this hot frying medium for varying lengths of time, typically on the order of from about 120 to about 240 seconds. While immersed, the french fried potatoes absorb a substantial quantity of the frying fat or oil, typically on the order of from about 12 to about 20% by weight of the french fried potato. Since this frying fat or oil comprises almost exclusively triglycerides, this frying procedure imparts a significant caloric content (about 9 calories per gram of oil absorbed) to french fried potatoes, as well as other foods fried in such triglyceride-based frying media.
Certain polyol fatty acid polyesters have been suggested as low calorie substitutes for these triglyceride fats and oils. For example, nonabsorbable, nondigestible sugar fatty acid esters or sugar alcohol fatty acid esters having at least 4 fatty acid ester groups with each fatty acid having from 8 to 22 carbon atoms have been used as partial fat replacers in low calorie food compositions. (See Mattson et al; U.S. Pat. No. 3,600,186; Issued Aug. 17, 1971.) Foods in which these polyol polyesters are particularly useful as partial or complete replacements for triglyceride fats or oils include products which are suitably prepared by frying.
Unfortunately, regular ingestion of moderate to high levels of nondigestible polyol polyesters which are liquid at body temperature can result in undesirable passive oil loss from the body, namely, uncontrollable leakage of such liquid polyesters through the anal sphincter. On the other hand, completely solid forms of nondigestible polyesters can have a sufficiently high solids content at body temperatures (i.e., 98.6.degree. F., 37.degree. C.) such that they present no anal leakage problem. However, these normally solid polyesters can taste waxy in the mouth when ingested.
As an alternative to these completely liquid or completely solid nondigestible/nonabsorbable polyol polyesters, certain intermediate melting polyol fatty acid polyesters have been developed that provide passive oil loss control, while at the same time reducing waxiness in the mouth. (See Bernhardt; European Patents 236,288 and 233,856; Published Sep. 9, 1987 and Aug. 26, 1987, respectively.) These intermediate melting polyol polyesters exhibit a unique rheology at body temperatures by virtue of their having a matrix which involves a minimal level of solids (e.g. about 12% or lower) that bind the remaining liquid portion. As a result, these intermediate melting polyol polyesters are sufficiently viscous and have a sufficiently high liquid/solid stability at body temperatures to provide passive oil loss control. An example of such intermediate melting polyol polyesters are those obtained by substantially completely esterifying sucrose with a 55:45 mixture of fully hydrogenated (hardstock) and partially hydrogenated soybean oil fatty acid methyl esters. (See Examples 1 and 2 of the above European patent publications.)
These intermediate melting polyol polyesters can be used as total or partial replacements for conventional triglyceride fats or oils in various food products, including cooking and frying oils. However, it has been found that certain foods such as french fried potatoes fried in frying fats containing substantial levels of these nondigestible intermediate melting polyol polyesters, particularly at levels in excess of about 50%, can give a significantly increased greasiness impression compared to french fried potatoes that have been fried in the digestible triglyceride fat or oil that the nondigestible polyol polyester has partially replaced. (In terms of physical characteristics, "greasiness" is, essentially, an unpleasant liquid viscosity effect, as contrasted with "waxiness" which relates to how a fat composition is sensed in the mouth and in particular relates to a sensation that the fat composition has a relatively high level of solids. In terms of organoleptic properties during french fry tasting, "greasiness" is described as a vaseline-like coating in the mouth.) However, as the proportion of triglycerides is increased relative to the intermediate melting polyesters to impart less greasiness to the french fried potatoes, the caloric content of the french fried potatoes increases accordingly.
In view of the foregoing, it would be desirable to identify reduced low calorie cooking, e.g. frying, fats containing high levels of nondigestible polyol polyesters, especially intermediate melting polyol polyesters in excess of 50% by weight, suitable for use without imparting excessive greasiness to french fried potatoes and other high moisture foods fried in such fats.